Multi-antenna systems, such as multiple-input multiple-output (MIMO) systems, use multiple antennas at both the transmitter and the receiver to communicate parallel streams of data. MIMO systems can achieve significant capacity gain over conventional single antenna systems. MIMO systems conventionally transmit these spatially multiplexed streams on the same frequencies. Orthogonal frequency division multiplexed (OFDM) systems, for example, may use the same set of subcarriers to communicate these parallel streams of data. Because the same frequencies are used, these spatially multiplexed streams need to be separated at the receiver using a decoding process. One issue with the decoding process is the complexity-performance tradeoff. A significant increase in decoding complexity is associated with higher decoding performance levels, especially for higher modulation levels (constellation size) and a greater number of spatial streams.
Thus there are general needs for systems and methods for decoding spatially multiplexed streams with lower complexity that achieve higher decoding performance levels.